The VIA Nano (formerly code-namedVIA Isaiah) is a 64-bitCPU for personal computers. The VIA Nano was released by VIA Technologies in 2008 after five years of development[1] by its CPU division, Centaur Technology. This new Isaiah 64-bit architecture was designed from scratch, unveiled on 24 January 2008,[2][3][4][5] and launched on May 29, including low-voltage variants and the Nano brand name.[6] The processor supports a number of VIA-specific x86 extensions designed to boost efficiency in low-power appliances.

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Unlike Intel and AMD, VIA uses two distinct development code names for each of its CPU cores. In this case, the codename 'CN' was used in the United States by Centaur Technology. Biblical names are used as codes by VIA in Taiwan, and Isaiah was the choice for this particular processor and architecture. It is expected that the VIA Isaiah will be twice as fast in integer performance and four times as fast in floating-point performance as the previous-generation VIA Esther at an equivalent clock speed. Power consumption is also expected to be on par with the previous-generation VIA CPUs, with thermal design power ranging from 5 W to 25 W.[7] Being a completely new design, the Isaiah architecture was built with support for features like the x86-64 instruction set and x86 virtualization which were unavailable on its predecessors, the VIA C7 line, while retaining their encryption extensions. Several independent tests showed that the VIA Nano performs better than the single-core Intel Atom across a variety of workloads.[8][9][10] In a 2008 Ars Technica test, a VIA Nano gained significant performance in memory subsystem after its CPUID changed to Intel, hinting at the possibility that the benchmark software only checks the CPUID instead of the actual features supported by the CPU to choose a code path. The benchmark software used had been released before the release of VIA Nano.[11]

On November 3, 2009, VIA launched the Nano 3000 series. VIA claims that these models can offer a 20% performance boost and 20% more energy efficiency than the Nano 1000 and 2000 series.[12] Benchmarks run by VIA claim that a 1.6 GHz 3000-series Nano can outperform the ageing Intel Atom N270 by about 40–54%.[13] The 3000 series adds an SSE4 instruction set, which was first introduced with IntelCore i7.

On November 11, 2011, VIA released the VIA Nano X2 Dual-Core Processor with their first ever dual core pico-itx mainboard. The VIA Nano X2 is built on a 40 nm process and supports the SSE4 instruction set.[14] Via claims 30% higher performance in comparison to Intel's Atom with a 50% higher clock.[15]

Out-of-order and superscalar design: Providing much better performance than its predecessor, the VIA C7 processor, which was in-order. This puts the Isaiah architecture in line with current offerings from AMD and Intel, except for Intel Atom which has an in-order design.

Instructions fusion: Allows the processor to combine some instructions as a single instruction, reducing power requirements and giving higher performance (the Atom uses a similar strategy in processing x86 instructions in a more 'whole' manner, rather than breaking them into RISC-like micro-ops).